This invention relates to the improvement of animal collars that are used for controlling fleas and ticks.
For some years pet animals have worn extruded plastic collars containing a pesticide. Such collars are exemplified by U.S. Pat. No. 4,250,838, which shows polyvinyl chloride and a pesticide, chlorpyrifos, extruded together and made into a pet collar which, when worn by the animal, controls fleas and ticks. Collars carrying pesticide of this general type have been widely used.
Pet owners, though thankful for the insect control aspect of these collars, worry that the collar could be caught on a tree or other protrusion and hang up the animal causing injury or death. This fear is particularly bad for cats that are want to climb trees.
Recent approaches to alleviate that concern have resulted in pet collars that become elongated sufficiently to allow the cat to slip its head out of the collar in the event of a hang up. One such collar uses a pesticide loaded plastic, with a portion of it containing a reduced cross-section in a multiloop serpentine arrangement and where the adjacent loops of the serpentine section are joined by thin plastic connectors. These connections are suppose to fail, allowing the serpentine section to straighten out and thus elongate the collar. Such an elongateable collar is unsatisfactory as the connections are so weak that the collar is easily extendable. The connections being less than 10 percent of the original collar are so weak that they tend to fail during ordinary usage. For instance, such connections fail when a 2.5 pound weight is used in a drop test as described hereinafter.
A second type of elongated collar that is known has a full sectioned pesticide filled plastic collar having an elastic band, one end of which holds the buckle. When an animal wearing such a collar is hung up, it can easily slip its head out of the collar. However, the strength of the elastic band is so low that almost any force will elongate it allowing the collar to be removed. Thus a scratching animal would easily remove it. Such a collar would not, therefore, provide the continuous pesticide control that is desired.
Accordingly, none of the known extendable pest control collars are satisfactory to solve the problem of continuous pest control.